‘OM’ represents the Self, which is the Supreme non-dual reality. The sound ‘A’ represents the dream-state and the sound ‘M’ represents the deep-sleep state. The waking state is superimposed on the ‘A’ sound because it is the first of the three states of consciousness and so is ‘A,’ the very first of the letters of the alphabet in all languages.

The dream is but a view within the mind of the impressions that reflected on the surface of the mental-lake during the waking state. Besides, the dream-state occurs between the waking and the deep-sleep state and comes second among the three sates of consciousness. And so, ‘U’ being next to ‘A’ in the order of sounds, and also between ‘A’ and ‘M,’ it is treated as representing the dream state.

On the ‘M’ sound of ‘OM’ is superimposed the deep-sleep state. The comparison between the last sound of ‘OM’ and sleep lies in that it is the closing sound of the syllable, just as deep-sleep is the final state of the mind in rest.

A short pregnant silence is inevitable between two successive OM-s. On this silence is superimposed the idea of the fourth-state known as ‘Turiya.’ This is the state of Perfect Bliss when the individual Self recognizes its identity with the Supreme.